No slot for memory card when Dual Sim Nokia 6

I'm very happy with my new Nokia 6 Dual Sim phone (I switched from Lumia 535). But there is no slot for memory card when there are two sims. That's so unfortunate, because I have already only internal shared storage 18,63 GB from 32 GB and 0,92 free memory from total 2,8 GB. Can I do something for more storage and memory?

Finally my phone unlocks only with code and without fingertip. Why is that?